Nellie Merrill, a telegraph operator and station agent in charge of a small station at Lowery, Arizona, has plighted her troth with Tom, a young foreman, of a nearby ranch, and the couple are looking forward to the time when Nellie can resign her position with the railroad and they can marry. Nellie’s beauty, however, has attracted the attention of Senior Gazanga, an unscrupulous Mexican, who owns and manages a large copper mine just outside of Lowery. One day while he is annoying Nellie with his unwelcome attentions, he goes a step too far and her frightened cry for aid is heard by Tom who happens to be outside of the station. The Mexican is quickly put to route in a manner which he regards as humiliating and he determines on revenge. Returning to his mine, he instructs his foreman to round up twenty-five or thirty of his companions whom he can trust and they start out with the determination to abduct the pretty operator. In the meantime, Nellie happens to see one of Gazanga’s scouts peering in at her through the window and becoming alarmed, sends a note to Tom, telling him of her fears and requesting him to join her at the station, which he does. Gazanga’s men approach the station and begin an attack. A thrilling battle ensues, continuing until the gallant defender’s find their ammunition is running short when Nellie, by unexpected means, manages to make her escape from the besieged building and returns with aid in time to save the day.